Deleting documents in Elasticsearch - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to delete a document by its ID.

Elasticsearch

DELETE /my_index/_doc/[1]

Drag options to blanks, or click blank then click option'

Aindex

B123

Cmy_id

Ddoc

Attempts:

3 left

💡 Hint

Common Mistakes

Using the index name instead of the document ID.

Using doc or other keywords instead of the actual ID.

The document ID to delete is specified after _doc/. Here, my_id is the correct ID placeholder.

2fill in blank

medium

Complete the JSON body to delete documents matching a condition.

Elasticsearch

{
  "query": {
    "term": { "status": [1] }
  }
}

Drag options to blanks, or click blank then click option'

A"status"

B"active"

Cactive

D"term"

Attempts:

3 left

💡 Hint

Common Mistakes

Not using quotes around the string value.

Using the field name instead of the value.

The value for the term query must be a string in quotes, like "active".

3fill in blank

hard

Fix the error in the delete by query request.

Elasticsearch

POST /my_index/_delete_by_query
{
  "query": {
    "match": { "[1]": "obsolete" }
  }
}

Drag options to blanks, or click blank then click option'

Astatus

Bdelete

Cquery

Dobsolete

Attempts:

3 left

💡 Hint

Common Mistakes

Putting the value instead of the field name as the key.

Using keywords like query or delete as field names.

The field name to match must be specified, here it is status.

4fill in blank

hard

Fill both blanks to delete documents where age is greater than 30.

Elasticsearch

{
  "query": {
    "range": {
      "age": { "[1]": [2] }
    }
  }
}

Drag options to blanks, or click blank then click option'

Agt

B30

Clt

Dage

Attempts:

3 left

💡 Hint

Common Mistakes

Using lt instead of gt.

Putting the number 30 in quotes.

The range query uses gt for 'greater than' and the value 30 to filter ages above 30.

5fill in blank

hard

Fill all three blanks to delete documents with status 'inactive' and priority less than 5.

Elasticsearch

{
  "query": {
    "bool": {
      "must": [
        { "term": { "status": [1] } },
        { "range": { "priority": { "[2]": [3] } } }
      ]
    }
  }
}

Drag options to blanks, or click blank then click option'

A"inactive"

Blt

C5

D"priority"

Attempts:

3 left

💡 Hint

Common Mistakes

Not quoting the status string.

Putting the number 5 in quotes.

Using wrong range operator like gt.

The term query needs the string "inactive". The range query uses lt for less than and the number 5 without quotes.

Practice

1.

Which Elasticsearch API method is used to delete a single document by its ID?

easy

A. GET method with document ID

B. DELETE method with document ID

C. POST method with document ID

D. PUT method with document ID

Solution

1. Step 1: Understand document deletion in Elasticsearch

   Deleting a single document requires specifying its ID and using the DELETE HTTP method.

2. Step 2: Identify the correct API method

   The DELETE method with the document ID is the standard way to remove one document.

3. Final Answer:

   DELETE method with document ID -> Option B

4. Quick Check:

   Delete single document = DELETE with ID [OK]

Hint: Use DELETE with document ID to remove one document fast [OK]

Common Mistakes:

• Using GET or POST instead of DELETE
• Trying to delete without specifying document ID
• Confusing _delete_by_query with single document deletion

2.

Which of the following is the correct syntax to delete a document with ID 123 from index products using Elasticsearch REST API?

?

easy

A. GET /products/_delete/123

B. POST /products/_doc/123/_delete

C. DELETE /products/_doc/123

D. PUT /products/_doc/123

Solution

1. Step 1: Recall the REST API syntax for deleting a document

   The correct syntax uses DELETE method on the path /index/_doc/document_id.

2. Step 2: Match the syntax with the options

   DELETE /products/_doc/123 matches DELETE /products/_doc/123 which is correct.

3. Final Answer:

   DELETE /products/_doc/123 -> Option C

4. Quick Check:

   Delete syntax = DELETE /index/_doc/id [OK]

Hint: DELETE + /index/_doc/document_id is the right syntax [OK]

Common Mistakes:

• Using POST or GET instead of DELETE
• Wrong URL path like _delete or missing _doc
• Using PUT which is for creating/updating

3.

Given this Elasticsearch _delete_by_query request to delete documents where status is "inactive":

{
  "query": {
    "term": { "status": "inactive" }
  }
}

What will be the result if there are 3 documents matching this query?

medium

A. Deletes 3 documents and returns success count 3

B. Deletes 0 documents because term query is incorrect

C. Deletes all documents in the index

D. Returns an error due to missing document ID

Solution

1. Step 1: Understand _delete_by_query behavior

   It deletes all documents matching the query, here documents with status "inactive".

2. Step 2: Apply to given query and data

   Since 3 documents match, all 3 will be deleted and success count will be 3.

3. Final Answer:

   Deletes 3 documents and returns success count 3 -> Option A

4. Quick Check:

   _delete_by_query deletes matching docs = 3 [OK]

Hint: Delete by query removes all matching docs, not just one [OK]

Common Mistakes:

• Thinking _delete_by_query needs document ID
• Assuming it deletes all documents regardless of query
• Confusing term query syntax

4.

What is wrong with this Elasticsearch delete request?

DELETE /users/_doc

It aims to delete a document but fails. Why?

medium

A. Missing document ID in the URL

B. Using DELETE instead of POST

C. Index name is incorrect

D. Missing request body with query

Solution

1. Step 1: Check the delete request URL format

   Deleting a document requires the document ID after _doc in the URL.

2. Step 2: Identify the missing part

   The request lacks the document ID, so Elasticsearch cannot identify which document to delete.

3. Final Answer:

   Missing document ID in the URL -> Option A

4. Quick Check:

   Delete URL needs document ID [OK]

Hint: Always include document ID after _doc in DELETE URL [OK]

Common Mistakes:

• Omitting document ID in delete URL
• Confusing DELETE with POST for deletion
• Thinking request body is needed for single delete

5.

You want to delete all documents from the orders index where the amount field is less than 100. Which Elasticsearch request correctly achieves this?

hard

A. DELETE /orders/_delete_by_query { "query": { "term": { "amount": 100 } } }

B. DELETE /orders/_doc { "query": { "range": { "amount": { "lt": 100 } } } }

C. POST /orders/_doc/amount_lt_100/_delete

D. POST /orders/_delete_by_query { "query": { "range": { "amount": { "lt": 100 } } } }

Solution

1. Step 1: Identify the correct API for deleting multiple documents by condition

   _delete_by_query is used with POST to delete documents matching a query.

2. Step 2: Check the query for amount less than 100

   The range query with "lt": 100 correctly matches documents with amount less than 100.

3. Step 3: Verify the request method and path

   POST /orders/_delete_by_query with the correct JSON body is the proper syntax.

4. Final Answer:

   POST /orders/_delete_by_query { "query": { "range": { "amount": { "lt": 100 } } } } -> Option D

5. Quick Check:

   Delete by query with range and POST = correct [OK]

Hint: Use POST _delete_by_query with range query for conditional deletes [OK]

Common Mistakes:

• Using DELETE method with request body (not supported)
• Using _doc endpoint instead of _delete_by_query
• Using term query instead of range for less than condition